Incidence of NUT carcinoma in Western Australia from 1989 to 2014: a review of pediatric and adolescent cases from Perth Children's Hospital.

BACKGROUND: NUT carcinoma (NC), previously known as NUT midline carcinoma, is a rare and very aggressive cancer that occurs in both children and adults. NC is largely chemoresistant, with an overall survival of less than 7 months. Because the carcinoma is not restricted to a particular organ, diagnosis is often a challenge. In the absence of a clearly determined incidence for NC, we sought to study the diagnosis of patients in a well-defined population. METHODS: We systematically reviewed records of all patients that presented to the Oncology Department of the Princess Margaret Hospital for Children from 1989 to 2014. This institution in the geographically isolated state of Western Australia has a catchment population of around 2 million. We then identified all high grade undifferentiated sarcomas or carcinomas in the 0-16 year age group. RESULTS: Over 26 years, we found 14 patients of 16 years or younger with undifferentiated malignant tumors. Of these, five tumors were positive by immunohistochemistry for the NUT/NUTM1 (Nuclear Protein in Testis) protein and/or the translocation t(15;19). Three patients presented with thoracic tumors, one with a para-spinal tumor, and one had an upper airway nasopharyngeal carcinoma. In all five cases, there was an initial response to therapy and then progression. This 26-year survey was conducted in a geographically isolated state with a well-defined population, and we determined an estimated incidence of NC of around 0.41 per million child years (0-16 yrs. of age) at risk. From three patients it was feasible to derive cell lines for further genetic analyses and drug screening. CONCLUSIONS: For the first time, the incidence of NC could be determined in a well-defined geographic area. The calculated rate of NC incidence is consistent with a history of under-recognition for this malignancy. These findings indicate that improved diagnostic detection of NC would enable better management and counselling of patients. Our findings emphasize the heterogeneity of NC, and they highlight the need to develop personalised therapy options, and to consider a diagnosis of NC in undifferentiated malignant tumors.

Podoplanin and SOX2 Expression in CIN 3-like Squamous Cell Carcinoma of the Cervix.

Squamous cell carcinoma (SCC) of the uterine cervix occasionally demonstrates a deceptive growth pattern that mimics endocervical crypt involvement by cervical intraepithelial neoplasia, grade 3 (CIN 3). Such CIN 3-like SCCs may be misinterpreted as noninvasive or minimally invasive leading to delays in diagnosis. Little is known of the factors that influence the growth patterns of cervical SCC but we suggested recently that CIN 3-like tumors might demonstrate "collective cellular invasion," which is characterized by a retained epithelial phenotype. This contrasts with the more overtly infiltrative growth of conventional SCC, which exhibits features suggestive of epithelial-mesenchymal transition. In the current study we investigated podoplanin (PP) and SOX2 expression in normal squamous epithelium, in CIN 3 and in 16 CIN 3-like SCCs 11 of which also showed a conventional invasive component. Compared with normal epithelium, CIN 3 often showed a focal loss of basal PP staining and most cases showed increased, typically diffuse, SOX2 expression. Although the immunohistochemical findings were not uniform, they generally supported collective cellular invasion in CIN 3-like tumor areas as these were often PP positive and showed diffuse SOX2 expression. In contrast, most conventional SCCs showed only focal SOX2 staining and they were typically negative, or only focally positive, for PP. The staining patterns did not reliably distinguish CIN 3 from CIN 3-like SCC. Small infiltrative tumor nests around the margins of CIN 3 or deeply invasive CIN 3-like SCC often showed a localized reduction in SOX2 expression suggesting SOX2 downregulation during the transition to invasive growth.

Cerebellar Differentiation in Ovarian Teratoma: A Report of 6 Cases.

Ovarian teratomas potentially demonstrate a wide range of tissue elements including central nervous system differentiation. The latter can include cerebellar tissue, which in our experience remains an under-recognized phenomenon. In the current study we present a review of 6 ovarian teratomas including 4 mature cystic teratomas and 2 immature teratomas showing cerebellar differentiation. Two cases were seen in consultation because the cerebellar elements were initially misinterpreted as immature teratomas. Two mature cystic teratomas focally demonstrated a distinct cerebellar architecture including folial type structures, but in all cases the cerebellar elements usually showed a less organized anatomic appearance, and sometimes these were concerning for immature teratomas upon initial examination. This concern was exacerbated in 5 cases by the presence of a cytologically immature and mitotically active neuronal component corresponding to the external granular layer of normal fetal and neonatal cerebellum. However, careful examination demonstrated the characteristic molecular, Purkinje and (internal) granular layers of cerebellum. Furthermore, while the external granular layer in teratomas strongly expressed Ki67, corresponding to the proliferative activity of this cellular compartment physiologically, immunostaining was often helpful in highlighting the preserved zonal pattern of cellular proliferation. The absence or minimal expression of SALL4, OCT3/4, and SOX2 was also helpful in this regard. Cytoplasmic OCT3/4 expression in osteoblasts was noted incidentally in 2 tumors, but further studies are required to determine whether this is a consistent and diagnostically useful finding.

Cervical intraepithelial neoplasia (CIN) 3-like squamous cell carcinoma of the cervix: a review of 14 cases with comparison of E-cadherin and cyclin D1 expression in the CIN 3-like and infiltrative tumour elements.

AIMS: To review the clinicopathological features of 14 cases of CIN 3-like squamous cell carcinoma (SCC) of the cervix and to investigate possible mechanisms of tumour invasion in the CIN 3-like and 'conventional' (infiltrative) tumour components. METHODS AND RESULTS: The median patient age was 43.4 years. Of the 12 cases with known stage, eight were stage IB and four were stage II. Initial biopsies were often misinterpreted as CIN 3 alone or CIN 3 with only superficial stromal invasion, and eight patients underwent multiple biopsy procedures prior to definitive diagnosis: upon review, an earlier diagnosis was possible in six of these cases. Nine tumours exhibited both CIN 3-like and conventional tumour components. The former usually demonstrated an E-cadherin-positive and cyclin D1-negative immunophenotype, whereas conventional SCC more often showed loss of E-cadherin and cyclin D1 staining at the margin of larger tumour nests and in smaller invasive clusters. CONCLUSION: Cervical SCCs demonstrating a CIN 3-like growth pattern continue to present diagnostic difficulty and are often misinterpreted as non-invasive/minimally invasive disease. The morphology and immunophenotype suggest a process of collective cellular invasion in CIN 3-like SCC, whereas corresponding conventional SCC elements show features consistent with epithelial-mesenchymal transition.

SOX2 Expression in Cervical Intraepithelial Neoplasia Grade 3 (CIN3) and Superficially Invasive (Stage IA1) Squamous Carcinoma of the Cervix.

The transcription factor SOX2 plays an important role in tissue development and differentiation. In the neoplastic context, SOX2 has been shown to potentiate tumor invasion, and increased SOX2 immunoreactivity has been demonstrated in a variety of epithelial and nonepithelial malignancies often correlating with adverse prognosis. There are limited data on SOX2 expression in cervical squamous neoplasia and in particular, no studies have compared staining in cervical intraepithelial neoplasia (CIN)3 and in superficially invasive (Stage IA1) squamous cell carcinomas (SCC). We examined SOX2 expression in 12 cervical biopsies showing CIN3 only and 30 specimens with an initial diagnosis of Stage IA1 SCC; 7 of the latter samples did not demonstrate residual invasive foci in the study slides but all showed CIN3. There was variable staining in CIN3 without stromal invasion but CIN3 adjacent to SCC was more often SOX2 positive with 70% cases showing diffuse staining. CIN within endocervical crypts often showed more extensive SOX2 expression and in some cases staining was restricted to areas of crypt involvement. In contrast to CIN, most SCCs were SOX2 negative and there was often an abrupt loss of expression at the tumor-stromal interface. In summary, CIN3 usually showed increased SOX2 expression compared with normal epithelium, particularly in areas of endocervical crypt involvement and adjacent to superficially invasive SCC. However, most invasive tumor cells were unstained suggesting downregulation of SOX2 during the initial stages of the invasive process. Progression of cervical squamous neoplasia may involve cyclical alterations in SOX2 activity.

PAX2 and cyclin D1 expression in the distinction between cervical microglandular hyperplasia and endometrial microglandular-like carcinoma: a comparison with p16, vimentin, and Ki67.

Microglandular hyperplasia (MGH) is a common endocervical alteration that in most cases presents no diagnostic difficulty. However, MGH rarely shows atypical features that may mimic endocervical neoplasia, while conversely endometrial carcinomas can show deceptively bland MGH-like appearances. It has been suggested that immunohistochemical analysis is useful in this context, but relatively few studies have specifically investigated microglandular pattern lesions and the results have been conflicting. In this study, we have examined a series of MGH (n=24), atypical MGH (n=2), and endometrial microglandular-like carcinomas (EMC, n=8), with a panel of antibodies including PAX2, cyclin D1, p16, vimentin, and Ki67. Loss of PAX2 staining was identified only in EMC but had relatively poor sensitivity for a malignant diagnosis (3/8 cases). Seven EMCs showed p16 expression and staining was diffuse (≥50% cells) in 6 cases, whereas all conventional MGH lesions were negative. However, 1 case of atypical MGH was also p16-positive. Cyclin D1, vimentin, and Ki67 did not reliably distinguish the benign and malignant microglandular lesions because of considerable overlap in staining patterns. In summary, none of the antibodies examined proved completely sensitive and specific, but a p16-positive/PAX2-negative phenotype favored a diagnosis of EMC. Pathologists should be aware that EMC, like some other types of endometrial carcinoma, are commonly p16-positive to avoid misinterpretation as a primary endocervical neoplasm. In practice, correlation of the histologic, immunohistologic, and clinical findings is necessary for accurate interpretation of microgandular-pattern lesions, particularly in small biopsy samples.

Extravascular migratory metastasis in gynaecological carcinosarcoma.

AIMS: Extravascular migratory metastasis (EVMM) is a potential mechanism of tumour spread reported most extensively in cutaneous melanoma. It has not been described previously in gynaecological malignancies. We describe EVMM in four gynaecological carcinosarcomas. METHODS AND RESULTS: Extravascular migratory metastasis was observed in an ovarian carcinosarcoma during routine diagnostic assessment. Twenty-three additional, randomly selected gynaecological carcinosarcomas (11 tubo-ovarian and 12 endometrial) were examined retrospectively and EVMM was identified in three of these. Other than the index case, EVMM was a focal finding, identified in 12-18% of slides. The malignant cells demonstrating EVMM appeared sarcomatoid and were distributed abluminally, partly or completely surrounding the endothelium. Affected vessels often showed mural fibrin deposition. Immunohistochemistry for α-smooth muscle actin (SMA), CD31, CD34, D2-40, laminin and type IV collagen was performed on the EVMM-positive cases. The perivascular malignant cells showed more consistent SMA and laminin immunoreactivity than the non-vascular tumour elements. CONCLUSIONS: Extravascular migratory metastasis is a hitherto unrecognized mechanism of tumour spread in gynaecological carcinosarcomas. The perivascular tumour cells appear to adopt a pericytic phenotype, and this may represent a specific pattern of epithelial-mesenchymal transition. Further studies with pericyte-specific immunohistological markers may better demonstrate the presence and possible prognostic significance of EVMM in gynaecological tumours.

Changes in thymic regulatory T-cell maturation from birth to puberty: differences in atopic children.

BACKGROUND: Characterization of regulatory immune pathways is a research priority for both the pathogenesis of allergic disease and potential therapeutic strategies. OBJECTIVE: The thymus is a rich source of regulatory T (Treg) cells, which offers a novel opportunity to document the maturation of these pathways beyond limited studies on small volumes of peripheral blood available from young children. METHODS: Thymus tissue was collected from children undergoing cardiac surgery (age, 1 week to 14 years), and skin prick testing was performed from 12 months of age. The ontogeny of Treg cell maturation and function was examined in atopic (n = 20) and nonatopic (n = 20) children by assessing their phenotype, enumeration, proliferation, and suppressive ability. RESULTS: Age-related changes in the thymic cytokine milieu paralleled the changes seen in peripheral immune function. Specifically, the thymic microenvironment is similarly T(H)2 skewed during the early postnatal period, and this undergoes age-related suppression as the T(H)1 (IFN-γ) response increased. We detected CD4(+)CD25(+)CD127(lo/-) forkhead box protein 3 (FOXP3)-positive Treg cells in the neonatal thymus. These cells suppressed the proliferative response to allogeneic stimulation of CD4(+)CD25(-) T cells dose dependently. In nonatopic children Treg cell turnover and suppressive function increased with age and paralleled the increase in global thymic FOXP3 mRNA expression, whereas in atopic children Treg cell maturation was significantly delayed compared with that seen in age-matched nonatopic children. CONCLUSION: These data suggest that the developmental changes in the thymus parallel the recognized changes in peripheral blood responses. There is also a developmental delay in the function of thymic regulatory cells in atopic compared with nonatopic children. These differences are fundamental to understanding early events that lead to immune dysregulation and might predispose to allergic disease.

Cyclin D1, E-cadherin and beta-catenin expression in FIGO Stage IA cervical squamous carcinoma: diagnostic value and evidence for epithelial-mesenchymal transition.

AIMS: Immunohistochemistry is helpful in distinguishing cervical neoplastic lesions from their histological mimics, but has contributed less towards the sometimes problematic distinction of in-situ and superficially invasive tumours. Epithelial-mesenchymal transition (EMT) may be a mechanism of invasion in cervical neoplasia and expression of EMT-associated proteins could prove useful in this diagnostic setting. METHODS AND RESULTS: Immunohistochemical expression of cyclin D1, E-cadherin and beta-catenin was assessed in 22 biopsy specimens from FIGO Stage IA cervical squamous carcinomas, all of which also included foci of cervical intraepithelial neoplasia (CIN) 3, nine biopsies of CIN 3 adjacent to carcinoma, and 10 cases of CIN 3 only. Most invasive tumour cells expressed cyclin D1 and showed a reduction in E-cadherin and beta-catenin staining. Nuclear beta-catenin expression was not observed. Cyclin D1 staining was reduced or showed altered distribution in most cases of CIN 3, while adhesion protein expression generally was preserved. However, altered protein expression similar to that of invasion was seen in some CIN lesions. CONCLUSIONS: Most superficially invasive cervical squamous carcinomas show immunophenotypical changes consistent with EMT. These alterations, particularly cyclin D1 expression, may be useful diagnostically. Similar changes in CIN 3 lesions may indicate the acquisition of increased invasive potential.

Correlation between invasive pattern and immunophenotypic alterations in endocervical adenocarcinoma.

AIMS: To assess the immunophenotypic changes associated with epithelial-mesenchymal transition (EMT) in endocervical adenocarcinoma, and correlate the findings with tumour morphology including growth pattern. METHODS AND RESULTS: Twenty-seven endocervical adenocarcinomas were studied using a panel of immunohistochemical markers to vimentin, cyclin D1, E-cadherin, beta-catenin, p16 protein and cytokeratin 7. There were 24 moderately differentiated and three poorly differentiated tumours. Fourteen of the moderately differentiated carcinomas showed a focal infiltrative component, typically towards the deep tumour margin (invasive front), comprising attenuated glands, small cell clusters and single cells. These foci typically showed cytological alteration including loss of cellular polarity and cytoplasmic eosinophilia, while immunohistochemistry demonstrated reduced cell membrane E-cadherin and beta catenin labelling, and expression of cyclin D1 and, in some cases, vimentin. Similar immunophenotypic changes were focally observed at the deep aspect of some larger 'conventional' tumour glands. No consistent changes were observed in the poorly differentiated carcinomas. CONCLUSIONS: Endocervical adenocarcinomas that demonstrate an infiltrative growth pattern show immunophenotypic changes consistent with EMT. Frequently, these are accompanied by a morphological alteration in the tumour cells and the changes exhibit a specific micro-anatomical distribution. Epithelial-mesenchymal transition may represent an important mechanism in the progression of some endocervical neoplasms.

Fascin expression in low-grade uterine endometrioid adenocarcinoma: correlation with microcystic, elongated and fragmented (MELF)-type alteration at the deep invasive margin.

AIMS: The actin-binding protein fascin appears to potentiate the migratory capacity of both normal and neoplastic cells. It has been suggested that microcystic, elongated and fragmented (MELF) glands might represent areas of active invasion within uterine low-grade endometrioid adenocarcinomas. Therefore, fascin immunoreactivity was investigated in a series of endometrial carcinomas specifically comparing expression in conventional tumour areas, foci of MELF-type invasion and in stromal elements. METHODS AND RESULTS: Fascin expression was assessed in 28 uterine endometrioid adenocarcinomas and the results compared with cytokeratin (CK) 7 expression and with tumour morphology and distribution. The conventional glandular component of most tumours showed only focal fascin reactivity (<10% cells positive), but staining was more prominent within the peripheral epithelial cells. Foci of squamous/morular type differentiation were also positive. The neoplastic epithelium in MELF-type invasion usually showed strong fascin immunoreactivity, often contrasting with the adjacent negative or more weakly stained conventional tumour glands. There was also staining of reactive stromal cells surrounding MELF foci. CONCLUSIONS: There are distinct micro-anatomical variations in fascin immunoreactivity within endometrial carcinoma. The localized increase in fascin expression in MELF-type epithelium supports the proposal that MELF changes represent areas of active tumour invasion.

Cytokeratin 19 expression in normal endometrium and in low-grade endometrioid adenocarcinoma of the endometrium.

The low-molecular-weight cytokeratin (CK) protein CK19 has been shown to have diagnostic use and prognostic significance in some types of human malignancy, but little is known of its distribution in normal endometrial mucosa or in endometrial endometrioid adenocarcinoma. However, we had observed that CK19 appeared to selectively label invasive tumor areas showing microcystic, elongated, and fragmented ("MELF") changes. Therefore, CK19 expression was assessed in 15 hysterectomy specimens showing normal proliferative, secretory, or atrophic endometrial appearances, and in 26 endometrioid adenocarcinoma cases with areas of MELF-type invasion. Normal endometrial glands were usually CK19 positive; however, there was more consistent expression in the functional layer, whereas basal zone epithelium was typically only focally stained. Proliferative epithelium frequently showed basal and apical cytoplasmic accentuation of staining. Endometrial carcinomas were also CK19 positive, but in most cases there was a distinct zonal pattern of expression with strong staining only in the central aspects of the larger tumor glands and weak-to-absent staining in peripheral glandular areas. In contrast, MELF-type tumor epithelium was consistently and strongly CK19 positive even when the adjacent "conventional"-type tumor glands were not stained. Intravascular tumor cells were also highlighted, including 2 cases in which this feature was not identified on hematoxylin and eosin stains. Thus CK19 immunohistochemistry was useful in showing the extent of myometrial invasion and subtle foci of lympho-vascular space invasion. Further studies are required to determine the mechanism and biologic significance of localized alterations in CK19 expression within endometrial neoplasms.

Thymic indoleamine 2,3-dioxygenase-positive eosinophils in young children: potential role in maturation of the naive immune system.

Eosinophils expressing indoleamine 2, 3-dioxygenase (IDO) may contribute to T-helper cell (Th)2 predominance. To characterize human thymus IDO+ eosinophil ontogeny relative to Th2 regulatory gene expression, we processed surgically obtained thymi from 22 children (age: 7 days to 12 years) for immunohistochemistry and molecular analysis, and measured cytokine and kynurenine levels in tissue homogenates. Luna+ eosinophils ( approximately 2% of total thymic cells) decreased in number with age (P = 0.02) and were IDO+. Thymic IDO immunoreactivity (P = 0.01) and kynurenine concentration (P = 0.01) decreased with age as well. In addition, constitutively-expressed interleukin (IL)-5 and IL-13 in thymus supernatants was highest in youngest children. Eosinophil numbers correlated positively with expression of the Th2 cytokines IL-5, IL-13 (r = 0.44, P = 0.002), and IL-4 (r = 0.46, P = 0.005), transcription factor signal transducer and activator of transcription-6 (r = 0.68, P = 0.001), and the chemokine receptor, CCR3 (r = 0.17, P = 0.04), but negatively with IL-17 mRNA (r = -0.57, P = 0.02) and toll-like receptor 4 expression (r = -0.74, P = 0.002). Taken together, these results suggest that functional thymic IDO+ eosinophils during human infant life may have an immunomodulatory role in Th2 immune responses.

Micro-anatomical variation in cellular proliferation in endometrial adenocarcinoma, and inverse correlation between Ki67 and cytokeratin 7 expression.

AIMS: To investigate micro-anatomical variations in proliferative activity within uterine endometrioid adenocarcinoma with particular emphasis on tumour areas comprising microcystic, elongated and fragmented ('MELF') glands. METHODS AND RESULTS: Ki67 immunoreactivity was assessed in 29 low-grade endometrial adenocarcinomas specifically comparing conventional tumour glands and areas exhibiting MELF-type alteration. Furthermore, since Ki67 expression differed between the peripheral and central aspects of larger neoplastic glands, these micro-anatomical compartments were assessed separately using a semiquantitative scoring system. Most MELF-type tumour elements were negative for Ki67 or showed only rare (< 5% cells) positivity. In contrast, peripheral conventional tumour glands showed prominent Ki67 labelling, but this was significantly reduced in central glandular areas. An inverse correlation between Ki67 and cytokeratin (CK) 7 expression was noted in many tumours. CONCLUSIONS: Endometrial adenocarcinomas show micro-anatomical variations in Ki67 expression and this is often inversely correlated with CK7 immunoreactivity. MELF-type tumour elements show minimal proliferative activity, a finding that initially appears unexpected for areas of purported active invasion. However, an inverse correlation between cell division and local invasion has been demonstrated in other malignancies, notably during epithelial-mesenchymal transition, and this may reflect a reversible alteration in cellular activity during neoplastic progression.

Galectin-3 expression in uterine endometrioid adenocarcinoma: comparison of staining in conventional tumor glands and in areas of MELF pattern myometrial invasion.

Endometrioid adenocarcinoma (EAC) of the uterus can show varying patterns of invasion, 1 of which, "MELF," is characterized by the presence of microcystic, elongated, and fragmented glands. However, at present, little is known of the functional alterations in neoplastic cells that are associated with the different patterns of myometrial invasion, including those in MELF. Galectin-3 is a widely distributed and multifunctional carbohydrate binding protein that has been shown to influence many aspects of tumor development and progression, but there are limited and conflicting data regarding galectin-3 expression in EAC. In this study, galectin-3 immunoreactivity was investigated in 22 EACs with specific comparison of staining in the "conventional" endometrioid-type tumor glands and in areas exhibiting MELF pattern invasion. Cytoplasmic galectin-3 was present in all tumors although <50% of cells were stained in approximately one-third of the cases. Nuclear staining was evident in 11 cases, but usually only in a small proportion of cells. The neoplastic epithelium within MELF areas showed a consistent reduction in protein expression, often contrasting with the adjacent galectin-3-positive conventional glands and reactive stromal cells. Conversely, intravascular tumor foci often showed cytoplasmic and nuclear galectin-3 immunoreactivity. The microanatomical variation in galectin-3 expression in EAC suggests that there are localized functional alterations in the neoplastic epithelium and the surrounding stroma during the invasive process. As MELF pattern invasion is associated with the loss of galectin-3 expression, there may be implications for the use of galectin inhibitors in the treatment of endometrial carcinomas and other malignancies.

Expression of cell cycle regulatory proteins in endometrial adenocarcinoma: variations in conventional tumor areas and in microcystic, elongated and fragmented glands.

Endometrial adenocarcinomas may show a distinctive pattern of invasion characterized by the presence of microcystic, elongated and fragmented glands, often most evident along the advancing tumor margin. Earlier, we have shown that these changes appear restricted to low-grade endometrioid carcinomas, many of which show focal mucinous differentiation and lymphovascular space invasion. However, the molecular alterations associated with this morphological alteration are not known. In this study, we have examined immunoreactivity for the cell cycle regulatory proteins cyclin D1, p16 and beta-catenin in 22 endometrial carcinomas, specifically comparing the results in conventional tumor areas and in foci in which the glands exhibited microcystic, elongated and fragmented appearances. The conventional neoplastic glands exhibited cyclin D1 and p16 expression in most cases, with >50% tumor cells positive in 8 cases and 11 tumors, respectively. Membranous expression of beta-catenin was usually preserved, with variable cytoplasmic and nuclear staining. Cyclin D1 and beta-catenin predominantly stained cells at the peripheral or basal aspect of the conventional glands, whereas p16 was more uniformly expressed centrally. Tumor foci composed of microcystic, fragmented and elongated glands showed strong expression of cyclin D1 and p16, sometimes in contrast to unstained contiguous or adjacent conventional neoplastic elements, and there was also loss or fragmentation of membranous beta-catenin staining. Intravascular tumor cells also expressed cyclin D1 and p16 and therefore the immunostains often highlighted subtle foci of lymphovascular invasion. The heterogeneous expression of cell cycle regulatory proteins within endometrial adenocarcinoma illustrates the importance of assessing microanatomical variations in immunoreactivity, particularly at the advancing margin of tumors. The upregulation of cyclin D1 and p16, together with loss of membranous beta-catenin expression in microcystic, fragmented and elongated glands, is similar to epithelial-mesenchymal transitions observed in other malignancies and suggests that this pattern of invasion represents an active rather than a degenerative cellular process.

Comparison of proliferation indices in primary adult-type granulosa cell tumors of the ovary and their corresponding metastases: an analysis of 14 cases.

Adult-type granulosa cell tumors (GCTs) of the ovary are generally low-grade malignancies, but late metastases are relatively common. Limited data suggest that recurrent GCTs may exhibit altered morphology and/or biologic behavior, but few studies have directly compared primary and recurrent tumors in individual patients. Fourteen GCTs in which histologic material was available from both the primary tumor and one or more metastases were reviewed, and the mitotic index (MI) and Ki-67 labelling index (KI) were evaluated using carefully specified methodology. The findings were also correlated with the time interval to tumor recurrence. The median interval to first recurrence was 6.6 years (range: 2.2 to 12.2 yr). There were only minor differences in tumor morphology between the primary and metastatic GCTs. None of the cases exhibited high-grade (sarcomatoid) transformation. There was a wide range in MI and KI in the GCTs and no consistent correlation was seen between these indices in the paired primary and recurrent neoplasms. There was also no association between the MI and the KI and the time interval to metastasis. In conclusion, metastatic GCTs generally maintain their morphologic features even after multiple recurrences over many years. Cellular proliferation in GCT is variable, and there is no uniform alteration in proliferation indices between paired primary and metastatic lesions. Therefore, data derived from the analysis of primary GCT may not always be applicable to recurrent tumors. These findings may have implications for management including the potential response of GCT to adjuvant therapies.

SF1 immunohistochemistry is useful in differentiating uterine tumours resembling sex cord-stromal tumours from potential histological mimics.

The aim of this study was to perform an immunohistochemical comparison of uterine tumour resembling ovarian sex cord-stromal tumour (UTROSCT) and other uterine lesions with sex cord-like (SCL) differentiation. Six UTROSCTs and 10 potential histological mimics with focal SCL elements were examined, the latter comprising three endometrial stromal nodules, three low-grade endometrial stromal sarcomas, three Müllerian adenosarcomas, and one case of adenomyosis. All cases were stained immunohistochemically for SF1, FOXL2, calretinin and inhibin, and for the less specific markers smooth muscle actin, desmin, CD10, CD56, CD99, cytokeratin, oestrogen receptor and progesterone receptor. Three, four, six and three UTROSCT expressed SF1, FOXL2, calretinin and inhibin, respectively. However, calretinin staining was focal (≤50% cells positive) in five of the cases. Three potential histological mimics demonstrated calretinin, FOXL2 and/or inhibin staining but none was SF1 positive. Most cases in both groups expressed the less specific immunomarkers. SF1 and FOXL2 immunoreactivity in UTROSCT further supports the concept that these tumours demonstrate genuine sex cord-stromal differentiation. While calretinin was the most sensitive UTROSCT marker, staining was usually focal and expression was also seen in two of 10 potential histological mimics. SF1 staining was 100% specific for UTROSCT in this series but this finding should be confirmed in larger studies.

Histological comparison of partial hydatidiform mole and trisomy gestation specimens.

The distinction between partial hydatidiform mole (PHM) and trisomy gestation is not always straightforward histologically and it is unclear which morphological features, alone or in combination, provide the greatest diagnostic accuracy. We performed a comparative review of 89 products of conception (POC) specimens including 54 PHMs and 35 trisomy gestations, assessing the following in each case: trophoblastic atypia, cistern formation, multifocal trophoblast proliferation, lace-like trophoblast, villous enlargement, large trophoblast inclusions, scalloped villous shape, stromal apoptosis, small round villous inclusions, and fibrillary stromal collagen. There was a significant difference in the presence of trophoblast atypia, cistern formation, multifocal trophoblast proliferation, lace-like trophoblast, large trophoblastic inclusions, small round villous inclusions, fibrillary collagen (all p<0.01), and apoptosis (p=0.028), between PHM and trisomy cases. Fibrillary collagen was more common in trisomy specimens whereas the other features were more common in PHMs. There was no significant difference in villous enlargement or scalloped villous shape between the two groups. The combination of cistern formation, multifocal trophoblast proliferation and large trophoblast inclusions correctly classified 83 (93.3%) of cases where the presence of at least two features was considered diagnostic of PHM. While cytogenetic analysis is arguably the gold standard for diagnosis, this study demonstrates that histological assessment permits accurate distinction of PHM and trisomic gestations in the great majority of cases.